Buoyed by stronger same-store sales and customer traffic levels, the National Restaurant Association’s Restaurant Performance Index (RPI) topped the 100 mark in September for the first time in three months. The RPI – a monthly composite index that tracks the health of and outlook for the U.S. restaurant industry – stood at 100.1 in September, up 0.7 percent from August and its highest level since June. In addition, September represented the first time in three months that the RPI stood above 100, the level above which signifies expansion in the index of key industry indicators. “The September increase in the Restaurant Performance Index was fueled by improvements in the same-store sales and customer traffic indicators,” said Hudson Riehle, senior vice president of the Research and Knowledge Group for the Association. “Among the forward-looking indicators, restaurant operators are more optimistic about sales growth in the months ahead, while their outlook for the overall economy remains cloudy.”